Abstract: The effects of quasi-nanoscale silver on preservation of both tomato juice and mixed juice from tomato and carrot were studied in this paper. The effective dose of quasi-nanoscale silver on tomato juice was found to be 0.1ppm,but when the same dose was applied to mixed juice from tomato and carrot, it was necessary to heating at 100? for 5min.Furthermore, the effects of quasi-nanoscale silver combined with nipagin A on preservation of both tomato juice and mixed juice from tomato and carrot were also investigated. The optimum combination pattern of quasi-nanoscale silver and nipagin A on both tomato juice and mixed juice is 0.04ppm of quasi-nanoscale silver and 200ppm of nipagin A ,and it must be remarked that when this combination pattern was used in preservation of mixed juice ,it was needed to heat mixed juice at 100? for 5 min.